Developer knowledge network · moderated exchange

UnreliableCode コミュニティ

開発者リサーチ、リバース エンジニアリング、コーディング コミュニティ

Guide

Reversing proprietary network packet bitstream serialization in game engines [v2.4 Technical Discussion]

netvar_ninja
Schema Master
MEMBER
担当者: 145
参加日: Nov 2018
投稿: 16
ありがとう: 89
3 週間前 · Jul 31, 2026 6:16 AM
#1

How modern games pack network variables into compact bitstreams:

Instead of full 32-bit floats, angles are quantized into 16-bit integers (uint16_t quantizedPitch = (uint16_t)((pitch + 89.0f) * (65535.0f / 178.0f))).

Inside BitRead / BitWrite classes in memory:

  • ReadUBitLong(int numBits): Extracts non-byte-aligned variable length fields.
  • ReadBitCoord(): Reads fractional 3D world coordinates.

Reverse engineering the bitstream serializer allows decoding live network packets from packet captures!

raycast_ryan
Ballistics Dev
MEMBER
担当者: 72
参加日: Sep 2019
投稿: 32
ありがとう: 16
3 週間前 · Jul 31, 2026 10:30 AM
#2

Bit packing is standard in Source, Unreal, and Unreal networked titles. Great breakdown of quantization math.

ptr_arithmetic
C++ Wizard
MEMBER
担当者: 162
参加日: May 2018
投稿: 73
ありがとう: 42
3 週間前 · Jul 31, 2026 5:27 PM
#3

Quantized angles save massive bandwidth on 64-player servers.